The aforementioned reciprocating pump is configured to reciprocally move a plurality of piston parts using a single driving source so as to be advantageous in view of the cost. The backward movement of a piston part allows fluid to be drawn into a pump chamber through an inlet port, and the forward movement of the piston part allows the drawn fluid to be discharged through an outlet port.
Specifically, two pump chambers which are provided in the left-right direction, left and right cams which are configured to reciprocally move piston parts provided respectively in the two pump chambers, and a drive unit configured to rotationally drive the left and right cams are provided. The cams are attached to a rotation shaft extending in the left-right direction and having both left and right ends rotatably supported via bearings so as to rotate integrally with the rotation shaft. Further, the drive unit includes a motor, a spur gear on the drive side which is externally fitted to a drive shaft of the motor so as to rotate integrally therewith, and a spur gear on the driven side which is attached to the rotation shaft between the left and right cams so as to be rotatable integrally therewith and mesh with the aforementioned spur gear to transmit a torque to the rotation axes of the cams (see, for example, Patent Literature 1).